1) Blood Loss :- B. with blood body loses both water and salt. so it will trigger release of vasopressin and aldosterone which will result in the reabsorption of water and salt from the filterate.
2) ADH secretion :- A. vasopressin increase the permeability of DCT for water which diffuses out from it.
3) Aldosterone release:- B. Aldosterone increase membrane permeability to Na+. as the ions move out actively, water diffuse out due to osmotic gradient resulting from ion movement.
4) alcohol consumption:- C. it actually decreases the water uptake. alcohol decrease the level of ADH. this results in less water uptake and excessive urination leading to dehydration.
5) sweating:- A. water loss by sweating decrease the plasma water level. it will stimulate secretion of ADH and increase water uptake in kidneys.
6) dehydration due to less water uptake:- A. same as above.
7) caffeine consumption:- C. caffeine and other xanthines inhibit Na+ reabsoption and increase glomerular filteration.
HOWEVER ONCE THEY ARE EXCRETED FROM THE BODY, THE BODY WILL TEND TO PRESERVE WATER AND SALT LOST DUE TO DIURETICS, SO IT WILL SECRETE ADH AND ALDOSTERONE TO INCREASE THEIR REABSORPTION. HERE THE ANSWER WILL BECOME "B".
8) eating salty foods:- A. salty foods increase the blood salt level. to tackle this, ADH is secreted and secretion of aldosterone is inhibited. this increase water uptake and decrease sodium reabsorption.
9) diabetes insipedus:-C. in diabetes, glucose is present in the filterate and final urine. due to presence of glucose in filterate is no more hypotonis to tissue fluid and so not loose water to it. so there is higher loss of water in urine. this leads to excessive urination, due to lesser water reabsorption, and increased thirst, due to high water loss.
10) severe diarrhea:- B. loss of chiefly water and salts in diarrhea will stimulate both ADH and aldosterone to increase their loss in urine to maintain homeostasis.
i hope it'll help